Screwdriver

A pic of my bike: Screwd.

Clean them again. Petrol turns to a varnish when it dries up and is a right bugger to remove. Sounds like you've still got some in there clogging things up. Try pulling off the feed hoses just to make sure you have petrol flow. Don't assume just because you have petrol at one end of a pipe, you'll have any at the other... Screwd.